1.1. What is Sun Ray Computing?

Sun Ray computing is a thin client implementation that offers
both desktop-like user functionality and sufficient speed and
reliability for mission-critical applications. Sun Ray Software
supports both hardware and software-based clients and runs on
both Oracle Linux and Oracle Solaris, including Oracle Solaris Trusted Extensions.

Other client-server models typically use combinations of remote
and local operating systems, applications, memory, and storage,
but the Sun Ray computing model moves all computing to a server.
Instead of running applications, storing data, and doing
computation on a desktop device like a PC, the Sun Ray model
simply passes input and output data between clients and the Sun
Ray server, where the operating system and applications are
located.

The following descriptions of the Sun Ray Computing attributes are based
on the Sun Ray Clients, although many of the points also apply to
Oracle Virtual Desktop Clients.

1.1.1. Stateless

Sun Ray Clients have no local disks, applications, or operating systems and are
therefore considered stateless. This setup is what makes them true thin
clients. Stateless devices are inexpensive to maintain because they do not require
administrators or technicians to install, upgrade, or configure software or to replace
mechanical components on the desktop.

A Sun Ray Client contains only a firmware module that performs
a small set of tasks: it sends keyboard and mouse events and
displays pixel data. If a desktop device contains an operating
system that can execute code at the request of a user, it has
state and it is not a true thin client.
This type of device requires updating and maintenance at the
desktop rather than server level and it is susceptible to
viruses.

1.1.2. Secure

Sun Ray Clients are also extremely secure. For instance,
managing USB mass storage devices, that is, controlling the
ability to enable or disable their use, is done at the server
or group level. This ability enables sites with particular
security or intellectual property concerns to eliminate many
of the risks imposed by PCs and other fat clients, which rely
on local operating systems, local applications, and local data
caches. Critical data can be compromised or lost when the
physical device hosting the "fat" client is stolen or damaged.

1.1.3. Available

A Sun Ray session is a group of services controlled by a
session manager and associated with a user through an
authentication token. The sessions reside on a server rather
than on the desktop. Because Sun Ray Clients are stateless, a
session can be directed or redirected to any Sun Ray Client on
the appropriate network or subnetwork when a user logs in or
inserts a smart card.

Although the session continues to reside on a server, the
session appears to follow the user to the new client. This
functionality, called hotdesking, provides the ability of
users to access their sessions from any client on their
network. Hotdesking can be implemented with smart cards or
without smart cards through the non-smart card session
mobility (NSCM) feature.

Most large Sun Ray implementations also include one failover
group of Sun Ray servers to ensure uninterrupted service
whenever a server is off-line. When a failover group is
configured, the Sun Ray Software optimizes performance by
spreading the computing load among the servers in the group.